Hydraulic valve control circuit and method for checking the function of a hydraulic valve control circuit

Abstract

A hydraulic valve control circuit of a hydraulic valve comprises an external voltage supply, an output stage having a voltage supply input and at least one output configured to actuate an actuator of the hydraulic valve, an overcurrent protective device disposed in a path between the external voltage supply and the voltage supply input, an enable input configured to activate and deactivate the output stage, and a switch configured to connect the at least one output to a fixed potential when the output stage is deactivated.

1. A hydraulic valve control circuit of a hydraulic valve comprising:
 an external voltage supply; 
 an output stage having a voltage supply input and at least one output configured to actuate an actuator of the hydraulic valve; 
 an overcurrent protective device disposed in a path between the external voltage supply and the voltage supply input; 
 an enable input configured to activate and deactivate the output stage; and 
 a switch controlled by the enable input and configured to connect the at least one output to a fixed potential when the output stage is deactivated so as to provide a short circuit path with respect to the actuator of the hydraulic valve between the at least one output and the fixed potential. 
 
     
     
       2. The hydraulic control circuit as recited in  claim 1 , wherein the overcurrent protective device includes a fusible cutout. 
     
     
       3. The hydraulic valve control circuit as recited in  claim 1 , wherein the overcurrent protective device includes a circuit breaker. 
     
     
       4. The hydraulic valve control circuit as recited in  claim 1 , further comprising a measuring circuit configured to measure a voltage at an output of the output stage. 
     
     
       5. The hydraulic valve control circuit as recited in  claim 4 , further comprising an error output indicating an error if the measuring circuit measures a potential at the output differing from the fixed potential by more than a prescribed threshold value. 
     
     
       6. The hydraulic valve control circuit as recited in  claim 1 , further comprising a second measuring circuit configured to measure a voltage at the first voltage supply input of the output stage. 
     
     
       7. The hydraulic valve control circuit as recited in  claim 1 , wherein the fixed potential is a ground potential. 
     
     
       8. The hydraulic valve control circuit as recited in  claim 1 , wherein the fixed potential is equal to the earth potential. 
     
     
       9. The hydraulic valve circuit as recited in  claim 1 , wherein the actuator actuating the hydraulic valve comprises a coil to generate a magnetic field. 
     
     
       10. A method to check the function of a hydraulic valve control circuit of a hydraulic control valve comprising:
 providing an external voltage supply; 
 actuating an actuator of the hydraulic control valve using an output stage having a voltage supply input and at least one output; 
 disposing an overcurrent protective device in a path between the external voltage supply and the voltage supply input; 
 activating and deactivating the output stage using an enable input; 
 connecting the at least one output to a fixed potential using a switch controlled by the enable input when the output stage is deactivated so as to provide a short circuit path with respect to the actuator of the hydraulic valve between the at least one output and the fixed potential; 
 measuring a voltage at an output of the output stage using a measuring circuit; and 
 indicating an error using an error output if the potential at the output differs from the fixed potential by more than a prescribed value. 
 
     
     
       11. The method as recited in  claim 10 , further comprising measuring a voltage at the first voltage supply input of the output stage using a second measuring circuit. 
     
     
       12. The method as recited in  claim 10 , further comprising testing functioning of the switch.